In medicine the switch from surgical interventions to minimally-invasive therapies is becoming established for serious illnesses.
Among the most frequent diseases with a fatal outcome are vascular angiopathies, with the resulting diseases such as heart attacks or strokes. The heart attack (myocardiac infarction=MI) is caused by diseases of the coronary vessels. In such cases arteriosclerotic plaque causes a thrombocyte activation and local thrombus formation. This can lead to a total occlusion (“blockage”) of coronary vessels and thereby to a blocking of the blood flow. The occlusion in a heart attack is treated nowadays in the majority of cases by a minimally-invasive PCTCA (percutaneous transluminal coronary angioplasty). In this treatment the constricted points of the coronary artery are expanded with a “balloon catheter”
A further example of the switch from surgical to minimally-invasive therapy is characterized by the treatment of diseases of the heart valves. Until a few years ago replacement of heart valves involved an operation on an open heart. In this procedure mechanical or biological prosthetic heart valves (aortic valve, pulmonary valve) are implanted or the existing valve opening is surgically reshaped (mitral valve and tricuspidal valve). This was associated with high risks and long recuperation times of up to six weeks for the patient. For a few years now there have been methods of treating heart valve stenoses with the aid of special catheters.
Very important for a successful and low-risk minimally-invasive therapy is the 3D presentation of the anatomy to be treated, of an organ for example.
The disadvantage of the new minimally-invasive therapies is that they can only be performed with the aid of x-ray fluoroscopy. This previously only supplied 2D images of organs, of the heart for example and of the catheters or tools located there. This meant that a spatial assignment was barely possible.
Further developments in x-ray image processing have led to 3D presentations of vessels or cavities with the aid of contrast media.
It is known from a paper titled “AXIOM Artis FD Systems / DynaCT-A Breakthrough in Interventional 3D Imaging” by Patrick Kurp, a “Reprint from Medical Solutions, Jan. 2005, page 46-51”, Order no. A91100-M1400-D105-1-7600, Reference CC 66105 SD 12043, that 3D soft tissue of non-moving organs can also be presented using x-ray technology. This type of method for 3D soft tissue creation, recognized in the medical imaging field as DynaCT imaging method, is described in DE 10 2004 057 308 A1, (which corresponds to U.S. Pat. No. 7,734,009) the content of which is included in this description. The term DynaCT (as capitalized) constitutes a registered trademark of the assignee of the present invention.
A distinct advance would be made with a C-arm x-ray apparatus currently being developed (CardDynaCT), with which images of 3D soft tissue and optionally high-contrast 3D images of the beating heart become possible by injecting contrast media.
Such a method is disclosed for example in DE 10 2005 016 472 A1, the contents of which is included in this description.
All known solutions however present the 3D x-ray images on 2D displays. The impression of a 3D image is achieved by volume rendering and rotation of the 3D image with the aid of a mouse of joystick.
With the aid of special eyeglasses, such as with polarization filters for example, it is possible to obtain an impression of a 3D image. However, this technology has not become established in medicine because of the additional eyeglasses required.
3D displays which manage without additional eyeglasses are known, made by companies such as newsight for example (see under http://www.newsight.com).
In these solutions the angles of view of the observer are detected and the polarization filter present in the display is controlled accordingly so that an impression of the 3D image is produced. This solution has the disadvantage that only one observer in each case perceives the impression of the 3D image. In addition the solution does not always operate reliably and has not established itself in the field of medical therapy.
A display system for image systems for reproducing medical images described in DE 100 36 143 C2, in which, instead of a display, a projector is used in the medical examination or intervention room, only allows 2D presentations however.
In the not yet published U.S. patent application Ser. No 11/093,561, “Creating a Stereoscopic Image Pair From Two Different Image Sources, Using Image Registration” a stereoscopic image impression is possible with the aid of two projectors and special eyeglasses worn by the observers. This solution has the advantage that a number of observers can see the 3D images; otherwise the disadvantages given above apply.
A method is described in the U.S. Pat. No. 6,672,165 B2 with which three-dimensional ultrasound images can be created holographically.
In the older DE 10 2008 015 312.5 a display system for reproducing medical hologram system is described in which the holographic images can be used for therapy, guidance and control. In practice however this is not a simple matter since many medical imaging systems, especially angiography systems, cannot generate any 3D data at a sufficiently high repetition rate in real time in order to make guidance possible. The known methods of 2D/3D overlaying are also not able to be used for holographic representation, so that it is not at all clear how such holographic images can be used for guiding an intervention.
DE 10 2005 051 102 A1 relates to a system and method for medical navigation, especially with C-arm and CT x-ray devices. In order to reduce the time outlay required for a medical navigation in percutaneous interventions, it is proposed to determine the position of a medical instrument in an object with the aid of projection images and to display the position in a three-dimensional structure image.
DE 10 2005 023 743 A1 describes a projection apparatus and a method for holographic reconstruction of scenes with a hologram matrix, an imaging system with a least one imaging means and an illumination system with sufficiently coherent light for illuminating a hologram encoded in the hologram matrix, with the light of the illumination device reconstructing the hologram. In a first step a reconstruction is undertaken as a Fourier transform of the encoded hologram in one plane of a first imaging means. In a second step the first imaging means forms an image of the hologram in a plane directly in front of the second imaging means. Simultaneously the second imaging means forms an image of the Fourier transform from the plane in an observer plane. In this way the reconstructed scene is provided enlarged in a reconstruction space stretched between the second imaging means and at least one observer window to at least one observer. The enlarged display of the hologram extends the size of the reconstruction space.